Ian Read is stepping down after eight years as chief executive of Pfizer.

During his tenure, Mr. Read helped reshape one of the world’s biggest pharmaceutical companies. Through deal making, he focused the company on its core business like vaccines and other specialized treatments. He acquired companies like Hospira, a maker of complicated generic versions of biotech treatments, and spun off divisions, such as an animal health business that is now the separately traded Zoetis.

But his time there may be best remembered for two deals that he failed to strike that made Pfizer a target for public criticism over corporate taxes.

Neither deal was born solely out of product necessity. Instead, the takeover bids were meant in large part to help Pfizer move its corporate headquarters abroad — and shrink its tax bills.

Mr. Read, an accountant by training, was outspoken in his defense of such deals. The United States tax code, which taxed American companies’ profits worldwide and at a higher rate than other countries, left his business at a disadvantage to foreign rivals, he argued. He said it was in his shareholders’ best interest to try and get the company the equivalent of a new passport.

“Our competitors don’t have to pay the penalty imposed on U.S. corporations bringing earnings back to America,” he wrote in a 2016 op-ed in The Wall Street Journal. “We can invest less — because of a broken tax system.”

The attempted deals drew anger from both ends of the political spectrum. Hillary Rodham Clinton decried such transactions, which she said eroded the tax base. Donald Trump called Pfizer’s bid for Allergan “disgusting.”

In late 2017, the Trump administration overhauled the American tax code. The changes reduced the corporate tax rate to 21 percent from 35 percent and lowered the tax rate on overseas earnings that were repatriated to the United States.

Pfizer took advantage. In January 2018, it announced that it would pay $15 billion in taxes over the next eight years to bring its overseas profits back to the United States. Mr. Read finally got a little of what he had sought all along.